The company's stock tanked following its float, forcing Vadon off the Forbes Billionaires list. Monday's news saw his net worth get a boost to around $800 million.

As the WSJnoted in early August, Zulily's sales growth slowed in the second quarter. The company blamed its lackluster results on one-off customers driven to the site by an advertising blitz. Zulily is now retooling its marketing strategy to attract repeat business.

Zulily's pitch to shoppers is not unlike QVC's: both offer deep discounts for a limited window of time. In Monday's acquisition announcement, QVC described their combined customer bases of young mothers and their older boomer counterparts as "highly complementary."

I'm a staff writer at Forbes, where I write about women entrepreneurs, workplace equality, and diversity in Silicon Valley and the tech world. Before taking on this beat, I spent three years covering retail and e-commerce, and the three before that chasing the super-rich fo...